title: An antioxidant screening assay based on oxidant-induced growth arrest in Saccharomyces cerevisiae.
abstract: This report describes a biological screening system to measure the antioxidant capacity of compounds using the oxidant-induced growth arrest response of Saccharomyces cerevisiae. Alternative methods using the nonphysiological free radical compounds such as diphenylpicrylhydrazyl and azinobis ethylbenzothiaziline-6-sulphonate (ABTS) only provide an indication of the ability of a compound to scavenge oxidants. In contrast, this yeast-based method can also measure the ability of a compound to induce cellular resistance to the damaging effects of oxidants. The screening assay was established against a panel of six physiologically relevant oxidants ranging from reactive oxygen species (hydrogen peroxide, cumene peroxide, linoleic acid hydroperoxide), to a superoxide-generating agent (menadione), reactive nitrogen species (peroxynitrite) and a thiol-oxidizing agent (diamide). The antioxidants ascorbate and gallic acid displayed scavenging activity and induced the resistance of cells against a broad range of oxidants using this assay. Lipoic acid, which showed no scavenging activity and thus would not be detected as an antioxidant using a nonphysiological screen was, however, identified in this assay as providing resistance to cells against a range of oxidants. This assay is high throughput, in the format of a 96-well microtitre plate, and will greatly facilitate the search for effective antioxidants.
authors.affiliation: School of Biomedical and Health Sciences, College of Health and Science, University of Western Sydney, NSW, Australia.
authors.forename: Ming J
authors.initials: MJ
authors.lastname: Wu
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: O'Doherty
authors.forename: Harvey R
authors.initials: HR
authors.lastname: Fernandez
authors.forename: Victoria
authors.initials: V
authors.lastname: Lyons
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Rogers
authors.forename: Ian W
authors.initials: IW
authors.lastname: Dawes
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Higgins
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000494:pharmacology; D003958:Diamide / Q000494:pharmacology; D026361:Reactive Nitrogen Species / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism; D013481:Superoxides / Q000494:pharmacology; D024483:Vitamin K 3 / Q000494:pharmacology
chemical_list: D000975:Antioxidants; D026361:Reactive Nitrogen Species; D017382:Reactive Oxygen Species; D003958:Diamide; D013481:Superoxides; D024483:Vitamin K 3